Impression tray



y 7, 1938. R. L. HUGHES 2,117,666

IMPRESSION TRAY Filed March 19, 1937 Patented May 17, 1938 UNITED STATES PATENT OFFICE IMPRESSION TRAY Raymond L. Hughes, Baltimore, Md. Application March 19, 1937, Serial No. 131,914

6 Claims.

This invention is a novel improvement in dental impression trays, and the principal object thereof is to provide a set of upper and lower trays having means for circulating cooling water therethrough, the trays being substantially no larger or more cumbersome than the ordinary trays now in use, and the water circulating in such a manner that the formation of air pockets in the water ducts is prevented.

Heretofore impression trays have been made through which water is circulated, but it has been found that the water did not circulate throughout the. entire extent of the water ducts due to the formation of air pockets at the corners and other portions of the trays remote from the inlet and outlet, and thus the trays were not uniformly cooled. My trays however obviate the above objection, and provide for proper regulated water circulation through the desired portions and the entire extent of the water ducts of the trays.

I will explain the invention with reference to the accompanying drawing which illustrates one practical embodiment thereof, to enable others to adopt and use same; and will summarize in the claims, the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawing:

Fig. 1 is a bottom plan view of a lower impression tray.

Fig. 2 is a top plan view of said lower impression tray with the upper cover plate removed, showing the location of the partition dividing the main water chamber of the base into two water a passages; also showing the arrangement of the water inlet and outlet pipes, and showing the ducts leading from the two water chambers to the tubes which form beads around the outer edges of the sides of the tray.

Fig. 3 is a section on the line 33, Fig. 1.

Fig. 4 is a section on the line 4-4, Fig. 1.

Fig. 5 is a top plan view of the upper impression tray.

Fig. 6 is a bottom plan view of the upper impression tray showing the bottom cover plate removed, exposing the partition dividing the main water chamber of the base into separate water chambers, also showing the ducts leading from the chambers into the tubes forming beads at 50 the inner end of the tray and around the outer edge of the sides of the tray.

Fig. 7 is a section on the line 1-1, Fig. 5.

As shown in Figs. 14, the lower impression tray A is preferably of the usual horseshoe shape, the tray consisting of spaced substantially U-shaped base plates I and 2 connected together by the inner and outer perforated side walls 3 and 4 of the tray, the space between the walls I, 2, 3, 4, forming a U-shaped water chamber. The outer. ends of the legs of the chamber are closed by 5 tubes 5 and 6 (Fig. 2) connecting the plates I and 2. Along the axis of the tray between the spaced plates I-2 is a partition wall I dividing the water chamber into substantially equal water passages 8 and 9. A water inlet nozzle I0 enters passage 9, and a water outlet nozzle I I leads from the other passage 8, as shown, the nozzles Ill and H preferably comprising tubes having their ends within the chambers 8 and 9 flattened as shown in Figs. 2 and 3 so that the water will enter and leave the tray under considerable pressure.

Around and conforming with the outer edges of the side walls 3 and 4 of the tray are tubes I2 and I3 respectively, forming beads, said tubes extending into and having their ends communicating with the water passages 8 and 9 respectively by means of ducts I4 and I5 formed in the tubes 5 and 6 of the water passages 8 and 9 as indicated.

Water is conducted by a hose or the like into the inlet nozzle Ill and fills the passage 9, the water from said chamber dividing and passing out through ducts I4 and I5 into and through the tubes I 2 and I3, and around and into the passage 8 at the other side of partition I, the water discharging from passage 8 through outlet nozzle I I. 30 Preferably the respective inlet and outlet nozzles I0 and I I are of cross-sectional area substantially equal to the combined cross-sectional areas of tubes I2 and I3, in order that a substantially constant steady flow of water will be maintained through the water circuit of the tray, and in such manner that formation of air pockets is prevented.

The upper tray B, as shown in Figs. 5-7, is provided with the usual suction cavity B in the base, the base being formed of spaced substantially semi-circular bottom plates 2Il2I connected together at their sides by the semi-circular perforated side wall 22 of the tray, the plates 20-2I being connected together along the substantially straight edge of the base by a tube 23, the plates 20, 2!, walls 22 and tube 23 forming a closed water chamber throughout the area of the base.

An axially disposed partition 24 divides the water chamber into separate passages 2526, the partition extending from the inner end to a point adjacent the tube 23 as shown in Fig. 6. A water inlet nozzle 30 enters one chamber, such as 26, and an outlet nozzle 3| leads from the other 55 chamber 25. Tube 23 has its ends communicating respectively with ducts 2'5 disposed in walls 220, at the outer corners of the water passages 25-26 of the base. A tube 28 forms a bead around the outer edge of the semi-circular side 22 of the tray and has its ends respectively communicating with ducts 29 also disposed in the walls 22a at the outer corners of the water passages 2526.

Water is introduced through the inlet nozzles 30 and fills the passage 26 of the base, the wa ter dividing in chamber 26, part of same passing into the duct 21 and through the tube 23 across the end of the base and entering the passage 25, part also of the water entering duct 29 and passing around through tube 23 and entering the passage 25 of the base, and remaining portion of the water passing directly around the outer end of partition 24 into the water passage 25 of the base, from which passage 25 the Water is discharged through outlet nozzle 3l. The gap in partition 24 adjacent tube 23 prevents formation of air pockets in its adjacent vicinity.

Preferably the sizes of the inlet and outlet nozzles 393l of the tray, and the gap in partition 24 are of such size or area that a continuous uninterrupted stream of water may be maintained in circulation throughout the Water circuit of the tray, the stream maintaining the chamber in the base of the tray completely filled at all times, and the circulation of Water being such that the formation of air pockets is rendered impossible. The ends of the nozzles within the chambers 25--26 are flattened to cause the water to enter and leave the tray under pressure.

I claim:

1. An impression tray comprising a hollow base having an axially disposed partition forming separate water passages having a Water inlet and outlet respectively; solid upstanding walls extending around part of the side of the base; and tubes extending along the outer edges of the walls and along the open parts of the side of the base, each tube having openings communicating with the respective passages.

2. In a tray as set forth in claim 1, said partition extending to a point adjacent the tube in the open part of the side of the base, whereby a portion of the water may pass directly from one passage to the other around the partition, the remaining portion passing through said tubes.

3. In a tray as set forth in claim 1, the inlet and outlet being disposed adjacent the partition at the end remote from the openings of the tubes, whereby the Water is caused to circulate throughout the entire areas of the passages Without formation of air pockets.

4. In a tray as set forth in claim 1, said inlet and outlet each comprising a tube having its inner end flattened to form a nozzle.

5. In a tray as set forth in claim 1, the inlet and outlet each being of cross-sectional area substantially equal to the combined cross-sectional areas of the tubes.

6. In a tray as set forth in claim 1, said partition extending to a point adjacent the tube in the open part of the side of the base whereby a portion of the water may pass around the end thereof, the inlet and outlet being disposed adjacent the partition at the end remote from the openings of the tubes, whereby the Water is caused to circulate throughout the entire areas 

